Rocket propulsion method



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Jul 28, 1959 OX/D/ZER YZLETZ ETAI. 2,896,403

ROCKET PROPULSION METHOD Filed Feb. 16. 1 9sz I INVENTORS: Alex Z/efz Don R. Carmady 2,396,403 Patented July 28, 1959 2,896,403 ROCKET PROPULSION Nm'rrror) Alex Zletz, Park Forest, and Don R. Carmody, Crete, Ill, assignors to Standard Oil Company, Chicago, 11]., a corporation of Indiana Application February 16, 1953, Serial No. 336,906

16 Claims. (Cl. 60-354) This invention relates to the generation of gas. More particularly, it relates to reaction propulsion by the hypergolic reaction of a liquid fuel and a liquid oxidizer. Still more particularly, the invention relates to a method of rocket propulsion by the hypergolic reaction of a fuel and a hydrogen peroxide oxidizer, which materials spontaneously react to generate gas at high pressure and high temperature.

Reaction propulsion is now being used for many aerial purposes. For many uses it is necessary to operate with a fuel system which is not dependent on atmospheric oxygen. This fuel system may consist of a single self-contained propellant or it may consist of a separate fuel and a separate oxidizer, i.e., a bipropellant system.

In the bipropellant system the fuel and the oxidizer are introduced separately and essentially simultaneouslyinto the combustion chamber of the reaction motor. The products of oxidation from the reaction of the fuel and the oxidizer are discharged through an orifice at the exit end of the combustion chamber and thereby produce the driving force. Because of the possibilities of electrical and/or mechanical failure of the auxiliary methods of ignition such as a spark or a hot surface, it is preferred to use a self-igniting fuel system. A fuel which is self-igniting, i.e., spontaneously combustible when contacted withan oxidizer, is known as a hypergolic fuel.

Temperature has an important effect on the hypergolic activity of fuels. The temperature at the earths surface may vary from a high of about +125 F. to a low of as much as 65 F.; in general temperatures below about -20 or 30 F. are exceptional. Thus surface-to-air missiles or rocket-driven aircraft should be capable of operation when the temperature of the fuel and the oxidizer at the moment of initial contact in the combustion chamber of the rocket motor is on the order of 20 F. Temperatures at high altitudes are frequently on the order of 65 F. and are known to approach 100" F. Thus an air-to-air missile should be able to operate satisfactorily when the temperature of the fuel and the oxidizer at the moment of initial contacting in the combustion chamber is on the order of 65 F.

The more common oxidizers are white fuming nitric acid, red fuming nitric acid and nitric acid-sulfuric acid mixtures. While these nitric acid oxidizers operate satisfactorily over a wide range of atmospheric temperatures they have important drawbacks. The nitric acid oxidizers are extremely corrosive; they have poor storage stability; they give oif toxic gases; and special precautions must be taken by personnel 'who handle these oxidizers.

Concentrated aqueous hydrogen peroxide solutions have excellent storage stability and do not give off harmful gas. However, these aqueous hydrogen peroxide solutions such as 90% hydrogen peroxide have the dis- 9()% hydrogen peroxide solution freezes at +12 F. The freezing point of 80% hydrogen peroxide is 9 F., but the activity of thissolution toward the prior art fuels is markedly lower than the 90% H solution. The freezing point of aqueous hydrogen peroxide solutions can be depressed by dissolving therein inorganic salts, preferably ammonium nitrate. Thus a solution containing 40 weight percent of ammonium nitrate and in which the hydrogen peroxide-water portion contains 90 weight percent of H 0 has a freezing point of about 30 F. A so-cailed 80% H O 3O% NH NO solution has a freezing point of below F.

Concentrated aqueous hydrogen peroxide solutions have been used as monopropellants by catalytically decomposing the hydrogen peroxide, using such catalysts as potassium permanganate or copper oxide. Since the decomposition products contain free-oxygen the monopropellant system is inefficient. However, fuels which are hypergolic with nitric acid oxidizers may be much less active or even inactive with concentrated H 0 solutions. Anhydrous hydrazine is usually considered to be the only fuel that is sufiiciently hypergolic with concentrated H 0 solutions to be practical; however, hydrazine has the disability of a comparatively high freezing point. Some fuels are operative with H 0 solutions in the presence of a H 0 decomposition catalyst. Furthermore, the prior art fuels are less effective with ammonium nitrate containing H 0 than with H 0 alone.

An object of this invention is a method of generating gas by the hypergolic reaction of a fuel and a hydrogen peroxide oxidizer. Another object is a method of reaction propulsion by the hypergolic interaction of a fuel and a hydrogen peroxide oxidizer. Still another object is a method of reaction propulsion by the hypengolic interaction of a hydrogen peroxide oxidizer and a fuel which contains appreciable amounts of miscible hydrocarbons, particularly non-hypergolic liquid hydrocarbons. A particular object is a method of generating gas by the hypergolic interaction of a defined fuel and an oxidizer consisting of an aqueous hydrogen peroxide solution containing dissolved ammonium nitrate. Another particular object is a method of rocket propulsion by the hypengolic interaction of a defined organic halophosphine and a defined hydrogen peroxide oxidizer when the temperature of the fuel and the oxidizer is about .70 F. Other objects will become apparent in the course of the detailed description of the invention.

A method has been discovered for generating gas, which gas may be used as a substitute for compressed air for certain purposes or for driving the turbine of a jet engine or for rocket propulsion, which method comprises contacting (1) A fuel consisting essentially of at least one member selected from the class consisting of (A) Monoaliphaticmonohalophosphirres which contain not more than 16 carbon atoms, (B) Monoaliphaticdihalophosphines which tain not more than 10 carbon atoms, and (C) Dialiphaticmonohalophosphines which contain not more than 12 carbon atoms and wherein each aliphatic radical contains not more than 8 carbon atoms, wherein the halogen radical in said phosphine is selected from the class consisting of chlorine and bromine, and (2) An oxidizer selected from the class consisting of (i) Aqueous hydrogen peroxide solutions which contain at least about 60 weight percent of H 0 and the remainder is essentially water, and (ii) Aqueous hydrogen peroxide-inorganic salt so- COH- ' advantage of comparatively high freezing points, mg,

aqueous hydrogen peroxide solutions and, particularly, ammonium nitrate containing solutions suitable for operation at temperatures as low as 60 F. The lower the initial temperature the less hydrocarbon tolerable in the. ea

Certain organic ,halophosphines ignite spontaneously when contacted with hydrogen peroxide oxidizers. The various halophosphines do not have equal hypergolic activity with the same oxidizer. However, by proper selection of thehalophosphine, it is possible to obtain a hyper golic reaction with a tolerable ignition delay when the phosphine and the oxidizer are at a temperature of about 70 F at the moment of initial contact in the gas generating chamber.

Certain monoaliphaticmonohalophosphines, monoali- .phaticdihalophosphines, dialiphaticmonohalophosphines and mixtures thereof are useful for the purposes of this invention These aliphatichalophosphines have the generi c empirical formula RRXP where P represents the element phosphorus, R represents an aliphatic radical, R represents a radical selected from the class consisting of aliphatic hydrogen, chlorine and bromine, and X represents a radical selected from the class consisting of chlorine and bromine. The term aliphatic as used herein is intended to include hydrocarbon radicals selected from the class consisting of paraflins and olefins. It has been found that the highly branched aliphatic substituents have desirably lower freezing points than the straight chain or slightly branched substituents. It is preferred'to use branched aliphatic substituents. The presence of unsaturated linkages in the aliphatic sub stituent improves thehypergolic activity. A particularly useful phosphine contains not only a highly branched aliphatic radical, but also contains one or more unsaturated linkages.

It has been found that the hypergolic activity of the various alip'hatichalophosphines is dependent upon the number of aliphatic radicals, upon the total number of carbon atoms contained in the phosphine, and upon the number of carbon atoms contained in each of the aliphatic radicals. In order to obtain a fuel which is usable at low temperatures, it is necessary that the monoaliphaticmonohalophosphines contain not more than 16 carbon atoms. The monoa1iphaticdihalophosphines must con tain not more than carbon atoms in the molecule. H

The dialiphaticmonohalophosphines must not contain more than 12 carbon atoms in the molecule and furthermore, no aliphatic radical must contain more than 8 carbon atoms.

Each halophosphine of this invention must contain at least one, and preferably two, halogen radicals selected from the class consisting of chlorine and bromine.

When it is desired to initiate, thecornbustio n at very low atmospheric temperatures, i.e., about 60 or -70 F., it is preferred to use the following fuels: monoalkyldihalophosphines which contain not more than 4 carbon atoms and dialkylmonohalophosphines which contain not more than 6 carbon atoms and wherein eachalkyl radical contains not more than 4 carbon atoms. The preferred species for operation at starting temperatures of about -70 F. are the monoethyldichlorophosphine, diethyl rionochlorophosphine and dimethylmonobromophos- P A mixed fuel which is suitable for the generation of gas for reaction propulsion when the fuel and the oxidizer are at a temperature of about 60 F. can be made by mixing an alkyl halophosphine with a miscible hydrocarbon. An effective amount of halophosphine must necessarily be present in the mixed fuel in order to obtain the hypergolic reaction. This amount will vary with both the type of hydrocarbon and the species of halophosphine. When using a monoethyldichlorophosphine and aromatic hydrocarbon mixture, as much as 60 volume percent of the mixed fuel may be aromatic hydrocarbons, for operations at temperatures .of above about +60 F. For operation at temperatures of about 60 F., only about volume percent of hydrocarbon is tolerable in the blend. In general, the higher the initial temperature of the fuel and the oxidizer, the more hydrocarbon tolerable in the mixed fuel. In general petroleum hydrocarbon fractions are suitable materials, for example, those fractions boiling between about 300 and 600 F. which correspond to the fuel requirement of military jet engines. Aromatic hydrocarbons which boil below about 600 F. are suitable hydrocarbons for this purpose. The low temperature hypergolic activity of the mixed fuel can be improved by using as the hydrocarbon component olefinic hydrocarbons such as thermally cracked naphthas and gas oils or turpentine.

The oxidizers of this invention may be either concentrated aqueous hydrogen peroxide solutions or aqueous hydrogenperoxidesolutions containing dissolved inorganic salts, for example, ammonium halides, sodium sulfate, sodium nitrate, etc.; for low temperature operation which requires a short ignition delay, ammonium nitrate must be used as the inorganic 'salt. The concentrated aqueous hydrogen peroxide solutions should containat least about 60 weight percent. of H 0 the remainder of the solution is essentially water.

The hypergolic activity of the aqueous hydrogen peroxide solution is' improved by increasing the concentration of the peroxide. Commercially available 90% H 0 solution is anexcellent oxidizer for operation at temperatures above about 0 F. For operation at temperatures below about 0 F., it is preferred to use aqueous H og-ammoniumnitrate solutions, such as, 90% 40 or "80%30% solutions.

Concentrated aqueous hydrogen peroxide solution as made commercially is virtually only H 0 and water. In order to improve storage stability small amounts of stabilizers may be added to the solution, e.g., sodium stannate, tetrasodium pyrophosphate, adipic "acid, tartari c acid; in general only trace amounts of stabilizers are added so 'that the solution consists essentially of hydrogen peroxide and water.

In order to depress the freezing point of aqueous hydro gen peroxide solutions soluble inorganic salts are dissolved therein, e.g., sodium nitrate, ammonium chloride and ammonium nitratehavebeen used. These salt-containing solutions are commonly designated in terms of the weight percent of salt in the total solution and the weight percent of hydrogen peroxide present in the aqueous portion of the solution, e.g., 90%"H O -40% NH NO indicates that the total aqueoushydrogen peroxide-nitrate solution consists of 4-0 weight percent of ammonium nitrate and weight percent of aqueous hydrogen peroxide com posed of 90 weight percent of H 0 and the remainder essentially water. This particular solution has a freezing point of about 30 F. A temperature of -F. is

attainable with an H O 30% NH NO solution.

It is' preferredto'operate in thepresence of ammonium nitrate because of the pronounced favorable effect on the hypergolic activity of the fuels of this invention.

It has, previously beenfound that monoaliphaticphosphines which contain between land 16 carbonatoz ns, dialiphaticphosphines which contain between 2 and 20 carbon atoms and wherein each aliphatic radical contains between 1 and 12 carbon atoms, and trialiphaticphosphines which contain between 3 and 24 carbonatoms and wherein each aliphatic radical contains between 1 and 12 carbon atoms arehypergolic with aqueous hydrogen peroxide oxidizers containing about H 0 at temperatures above about -20 F. Examples of these fuelsare: tributylphosphine, dodecylphosphine and dioctylphosphine. The hypergolic activity of these fuels at lower temperatures can be great ly improved by adding thereto small amounts of the above defined halophosphines, i.e., the halophosphines have a synergistic catalytic effect on the' activity of aliphatic phosphines. For low temperatures. the halophosphine Phosphine fuel should contain between about 1 and 15 volume percent of halophosphine, preferably the dihalo phosphine.

Monoethyldichlorophosphine (C H PCl was prepared by the method of Karasch, Jensen and Weinhous, J. Org. Chem., 14, 429 (1949) using 137 g. of PCl and 100 g. of lead tetraethyl. The two reagents were heated for 11 hours in a nitrogen atmosphere under total reflux; the reflux temperature rose from 85 C. to 118 C. A 35% yield was obtained of a fraction boiling between 112122 C. at 750 mm. pressure. The literature boiling point of monoethyldichlorophosphine is 1 14-1 17 C.

The ignition characteristics of various fuels were studied using a drop test. This method utilizes a test tube, 1 in. x 4 in., containing about 0.5 ml. of oxidizer. The fuel to be tested was drawn into a hypodermic syringe. It was then ejected forceably against the oxidizer surface by depressing the syringe plunger. By this method amounts of fuel of as little as 0.01 mi. can :be added. Low temperaturetests were carried out by cooling the test tube and the oxidizer contained therein by means of a bath; a drying tube inserted into the top of the test tube excluded moisture. The fuel was cooled separately to the desired test temperature. By supercooling at was possible to carry out tests at temperatures below the freezing point of the fuel and/ or the oxidizer.

The ignition delay, which is the time elapsing between the addition of fuel to the oxidizer and visual igni tion thereof, was determined visually as either (a) very short which corresponds to substantially instantaneous ignition, (b) short, which corresponds to substantially less than 1 second, and (c) more than 1 second, which time was determined by a stop watch.

The following tests illustrate the activity of some of the alkyl halophosphines of this invention and hydrazine With hydrogen paroxide oxidizers.

Test 1 In this test several runs were made with monoethyldi chlorophosphine at different temperatures using 0.5 m1. of various H 0 solutions as the oxidizer. A run was made with mono(n-octyl)phosphine for comparison purposes.

* Monoethyldiehlorophosphine. b Mono (n-oetyl) phosphine.

These data show that the halophosphines are much more hypergolic than are the alkylphosphines.

Test 2 In order to observe the effectiveness of halophosphine with oxidizers consisting of aqueous hydrogen peroxideammonium nitrate solutions, runs were made using 0.5 ml. of aqueous hydrogen peroxide-ammonium nitrate solutions as the oxidizer, and monoethyldichlorophosphine as the fuel.

Oxidizer added, H202- NH NO percent Fuel T emp Ignition delay Very short.

Short.

N o ign)ition (effervescenc 2sec.

a Monoethyldiehlorophosphlne. b Mono (n-oetyDphosphine.

Test 3 For comparative purposes hydrazine was contacted at various temperatures with either 90% H 0 or H 0 solutions as the oxidizer.

Run H2O: Fuel Temp., No. oxidizer, added, F. ignition delay percent m 0.05 +70 Very short. 80 0. 03 +70 Short. 80 0.10 +14 N o ignition (efiervescence). 90 0.03 +14 Very short. 9040 0. 03 +14 N o ignition.

Test 4 The hypergolic activity of mixtures of toluene and monoethyldichlorophosphine was tested at various blends and various temperatures using 0.5 ml. of various oxidizers.

Toluene Fuel Oxidlzer Run content, adde H2O2- Temp Ignition delay No. vol. m1. NH4NO3, F.

percent percent l7- 22 0.02 90 +70 Very Short. 18- 3O 0. 06 90 +70 Do. 19 0. 06 90 +70 Do. 0.12 90 +70 Do. 0.20 90 +70 Do. 0. 02 90-40 +70 D0. 0. 04 90 0 2 sec. 0.07 90 Do. 0.06 90-40 -42 Very short. 0.03 80 +70 Do. 0. 07 80 4 see. otyl) phosphine and benzene were tested for comparison. 0. 10 90 +70 N o ignition. 0. 15 90 +70 Short.

These runs show the greater hypergolic activity of the halophosphine-aromatic hydrocarbon mixed fuels over the alkylphosphine mixed fuels.

Test 5 Mixed fuel added ml.

Run N o. Ignition delay 5 9. 9 ooooo \rqqqq 5 80% 11 02-207 NH4NO3.

3 80% Ham-20% NH4C1.

4 80% H o satd. NaNO; (would not dissolve 20% of salt).

These runs show the extremely favorable effect on activity of ammonium nitrate in the hydrogen peroxide oxidizer.

It is obvious from the data presented above that this invention can be used to generate gas at high pressure. This gas can be used for operating machinery such as compressed air hammers or for aircraft catapults; another important use for this high pressure gas is in the starting of the turbines of jet-type engines. The invention is particularly useful for operations which require a compact power plant that is able to produce a large amount of energy over a very short period of time, when the fuel and oxidizer are at low atmospheric temperachamber at the launching site.

tures. Other examplesof uses of this. invention are: the rocket-assisted takeoff or flight. offairci'aft; aerial missiles; boosters for surface. vehicles. i

The relative proportion of oxidizer-to-fuel used will depend upon the type of operation, the temperature of operation and the type of fuel and oxidizer beingused. When using a 80% H O '30% NH NO T solution as the oxidizer and dibutylmonochlorophosphine as the fuel, between about 4 and 5 volumes of oxidizer are needed per volume of fuel.

By way of example this invention is applied to the propulsion of a surface-to-air missile. The annexed figure which forms a part of this specification shows schematically the bipropellant feed system and the motor of.

this missile. This same type of missile could be used as an air-to-air missile. This missile is suitable for operations wherein the fuel and the oxidizer can be maintained at a temperature high enough to insure at least a short ignition delay, e.g., when using the above oxidizer and fuel combination, a terriperatureof about -70 F.

In the drawing vessel 11 contains a quantity of gas at high pressure; this gas must be inert with respect to the oxidizer and the fuel; suitable gases are nitrogen and helium. Herein helium is used as the inert gas. Helium from vessel 11 is passed through line 12 and through valve 13 which regulates the flow of gas to maintaina constant pressure beyond valve 13. From valve 13 helium is passed through lines 14 and 16 into vessel 17 the oxidizer out of vessel 17 through line 21 to valve 22. Valve 22"is a solenoid actuated throttling valve. Suitable electrical lines connect valve 22to an electrical source and operating switch (not shown) at the control The oxidizer is passed through line 23 and injector 24 into combustion chamber 26. Combustion chamber 26 isprovided with an outlet nozzle 27.

Vessel 19 contains the fuel. constructed to withstand the high pressure imposed by the helium gas. The gas pressure forces fuel from vessel 19 through line 28 to solenoid actuated throttling valve 29. Valve 29 is similar in construction and in actuation to valve 22. The fuel is passed through line 31 and injector 32 into combustion chamber 26.

Valves 22 and 29 are ofsuch a sizeand setting that a predetermined ratio of oxidizer-to-fuel is passed into combustion chamber 26. Injectors 24 and 32 are so arranged that the streams of oxidizer and fuel converge and contact each other forcibly, resulting in a 'very thorough intermingling of the fuel and the oxidizer.

The missile is launched by activating the solenoids on valves 22 and 29. In this example 4.2 volumes of 80%- 30% solution per volume of halophosphine is introduced into the combustion chamber. The oxidizer and the fuel react almost instantaneously upon contact in the combustion chamber; a large volume of very hot gas is produced in the combustion chamber, which gas escapes through orifice 27. The reaction from this expulsion of gas drives the missile toward its target.

Thus having described the invention, what is claimed l. A method of generating gas, which method comprises injecting separately and essentially simultaneously into the combustion chamber of a gas generator ('1) a hypergolic fuel consisting essentially of a member selected from the class consisting of (i) monoorg'anicmonohalophosphines containing not more than 16 carbon atoms, (ii) monoorganicdihalopliosphines containing not more than carbon atoms and (iii) diorganicmonohalophosphines containing not more than 12 carbon atoms and not more than 8' carbon atoms in an organic group, wherein the organic groups in (i), (ii) and (iii) above are alkyl and the'halogen radicals are selected from the classconsistin'g of chlorine and bromine and Vessels 17 and 19 are (2 an oxidizer selected from the class consisting of- (a) aqueous hydrogen peroxide solutions consisting of at least about weight percent of H 0 and the remainder essentially water and (b) aqueous hydrogen peroxide-ammonium nitrate solutions wherein the hydrog en peroxide water portion is the predominant com ponent and consistsof at least about 80 Weight percent of H 0 and the remainder essentially water, in an amount and ate rate sufficient to initiate a hypergolic reaction Witlrand to support combustion of; the fuel.

2. The method of claim 1 wherein said fuel is monoethyldichlorophosphine. V

The method of claim 1 wherein said fuel is dibutyl monochlorophosphine. I

4.v Themethod of claim 1 wherein said fuel is diethylmouochlorophosphine.

5. The method of claim 1 wherein said oxidizer conr sists of about. 80 weight percent of H 0 and the remainder essentially water.

6. The method of claim 1 wherein said oxidizer consists of about weightpercent of H 0 and the remainder essentially water.

7. The method of claim 1 wherein said oxidizer consists of a solution of hydrogen peroxide, water and ammonium nitrate, wherein the nitrate content is about 30 weight percent and the hydrogen peroxide-water portion consists of about 80 weight percent of H 0 and the re mainder essentially water;

8. The method of claim 1 wherein said oxidizer con-' sists-of a solution of hydrogen peroxide, water and ammonium nitrate, wherein the nitrate content is about 40 weight percent and the hydrogen peroxide-water portion consists of about 90'weight percent of H 0 and the remainder essentially water.

9. A method of generating gas, which method com prises injecting separately and.essentially simultaneously into the combustion chamber of a gas generator (1) a hypergolic mixed fuel consisting essentially of (1)" a liquid miscible hydrocarbon and (II) monoethyldichlorophosphine and (2) an oxidizer selected from the class consisting of (a) aqueous hydrogen peroxide solutions consisting of at least about 80 weight percent of H 0 and the remainder essentially water, and (11) aqueous hydrogen peroxide-ammonium nitrate solutions wherein the hydrogen peroxide-water portion is the predominant component and consists of at least about 80 weight percent of H 0 and the remainder essentially water, in an amount and at a rate sufiicient to initiate a hypergolic re action with and to support combustion of the mixed fuel.

10. The method of claim 9 wherein said hydrocarbon is a liquid petroleum fraction boiling between about 300 and about 600 F.

U 11. The method of claim 9 wherein said hydrocarbon 16S0dig1uld aromatic hydrocarbon boiling below about 12. The method of claim 9 wherein said hydrocarbon is a liquid olefin boiling below about 600 F.

13.. a method of generating gas, which method comprises in ecting separately and essentially simultaneously into the combustion chamber of a gas generator (1) a hypergolic mixed fuel consisting essentially of (l) a liquidmiscible hydrocarbon and (II) 'diethylmonochlorop'hosphine and (2) an oxidizer selected from. the class consisting of ([1) aqueous hydrogen peroxide solutions consisting of at least about 80 weight percent of H 0 and the remainder essentially water, and ([2) aqueous hydrogen peroxide-ammonium nitrate solutions wherein the hydrogen peroxide-water portion is the predominant component and consists of at least about 80 weight percent of H 0 and the remainder essentially water, in an amount and at a rate suliicient to initiate a hypergolic ieaction with and to support combustion of the mixed uel.

14. A method of gas generation, which method comprises injecting separately and essentially simultaneously into the combustion chamber of a gas generator (1) a hypergolic fuel consisting essentially of (A) alkyl phosphines selected from the class consisting of (i) monoalkylphosphines containing not more than 16 carbon atoms, (ii)dialky-lphosphines containing not more than 20 carbon atoms and not more than 12 carbon atoms in an alkyl radical, and (iii) trialkylphosphines containing not more than 24 carbon atoms and not more than 12 carbon atoms in an alkyl radical, and (B) between about 1 and 15 volume percent basedon fuel of a halophosphine selected from the class consisting of (i) monoorganicmonohalophosphines containing not more than 16 carbon atoms (ii) monoorganicdihalophosphines containing not more than 10 carbon atoms and (iii) diorganicmonohalophosphines containing not more than 12 carbon atoms and not more than 8 carbon atoms in an organic group, wherein the organic groups in (i), (ii) and (iii) above are alkyl and the halogen radicals are selected from the class consisting of chlorine and bromine and (2) an oxidizer selected from the class consisting of (a) aqueous hydrogen peroxide solutions consisting of at least about 80 weight percent of H and the remainder essentially water and (b) aqueous hydrogen peroxide-ammonium nitrate solutions, wherein the hydrogen peroxide water portion is the predominant component and consists of at least about weight percent of H 0 and the remainder essentially water, in an amount and at a rate sufiicient to initiate a hypergolie reaction with and to support combustion of the fuel.

15. The method of claim 14 wherein said halophosphine is monoethyldichlorophosphine.

16. The method of claim 14 wherein said aliphatic phosphine is tributylphosphine.

References Cited in the file of this patent FOREIGN PATENTS Great Britain June 4, 1952 OTHER REFERENCES 

1. A METHOD OF GENERATING GAS, WHICH METHOD COMPRISES INJECTING SEPARATELY AND ESSENTIALLY SIMULTANEOUSLY INTO THE COMBUSTION CHAMBER OF A GAS GENERATOR (1) A HYPERGOLIC FUEL CONSISTING ESSENTIALLY OF A MEMBER SELECTED FROM THE CLASS CONSISTING OF (I) MONOORGANICMONOHALOPHOSPHINES CONTAINING NOT MORE THAN 16 CARBON ATOMS, (II) MONOORGANICDIHALOPHOSPHINES CONTAINING NOT MORE THAN 10 CARBON ATOMS AND (III) DIORGANICMONOHALOPHOSPHINES CONTAINING NOT MORE THAN 12 CARBON ATOMS AND NOT MORE THAN 8 CARBON ATOMS IN AN ORGANIC GROUP, WHEREIN THE ORGANIC GROUPS IN (I), (II) AND (III) ABOVE ARE ALKYL AND THE HALOGEN RADICALS ARE SELECTED FROM THE CLASS CONSISTING OF CHLORINE AND BROMINE AND (2) AN OXIDIZER SELECTED FROM THE CLASS CONSISTING OF (A) AQUEOUS HYDROGEN PEROXIDE SOLUTIONS CONSISTING OF AT LEAST ABOUT 80 WEIGHT PERCENT OF H2O2 AND THE REMAINDER ESSENTIALLY WATER AND (B) AQUEOUS HYDROGEN PEROXIDE-AMMONIUM NITRATE SOLUTIONS WHEREIN THE HYDROGEN PEROXIDE-WATER PORTION IS THE PREDOMINANT COMPONENT AND CONSISTS OF AT LEAST ABOUT 80 WEIGHT PERCENT OF H2O2 AND THE REMAINDER ESSENTIALLY WATER, IN AN AMOUNT AND AT A RATE SUFFICIENT TO INITIATE A HYPERGOLIC REACTION WITH AND TO SUPPORT COMBUSTION OF THE FUEL. 